Active underground zinc, lead, copper and silver mine in continuous production since 1857, now operated by Boliden AB.
Zinkgruvan is an underground polymetallic mine located in Askersund Municipality, Örebro County, in the Bergslagen district of south-central Sweden, approximately 250 kilometres southwest of Stockholm. The deposit, a stratiform massive sulphide body of zinc, lead, silver and copper extending over five kilometres along strike and reaching depths of 1,400 metres or more, was known to exist since the sixteenth century but was not exploited commercially until 1857, when large-scale production began under the Belgian company Vieille Montagne. The original concentrator was situated at Åmmeberg on the shore of Lake Vättern, with ore carried approximately five kilometres to it by narrow-gauge railway.
In the mid-1970s the operation was fundamentally reorganised: a new shaft, P2, was sunk to access deeper ore, and a new concentrator and tailings facility were established at the mine site itself, with the Åmmeberg plant closing between 1975 and 1977. Vieille Montagne merged with Union Minière in 1990, which was acquired by North Limited of Australia in January 1996; North renamed the Swedish entity Zinkgruvan Mining AB in 1997. Rio Tinto acquired North in August 2000.
In June 2004 Lundin Mining, then trading as South Atlantic Ventures, bought the mine from Rio Tinto for USD 101 million. Under Lundin a copper processing circuit was commissioned in 2010, adding a third significant revenue stream. Boliden AB acquired Zinkgruvan Mining AB from Lundin Mining in April 2025.
The Zinkgruvan deposit lies within the Paleoproterozoic Bergslagen volcanic arc of south-central Sweden. Its ore bodies are stratiform, well-banded and massive, dominated by sphalerite and galena, with subordinate chalcopyrite in a substratiform copper stockwork underlying the main zinc-lead mineralisation. The deposit was identified as early as the sixteenth century but lacked commercial exploitation due to technological constraints and low demand for zinc, which had limited industrial use before the nineteenth century.
Large-scale underground mining began in 1857, initially under the ownership of the Belgian company Vieille Montagne, one of Europe's principal zinc producers of the era. Early operations used manual and semi-mechanised methods. The processing plant was located at Åmmeberg, a village on the shore of Lake Vättern approximately five kilometres from the mine, and ore was transported there by narrow-gauge railway. The mine was then known informally as the Åmmeberg mines, or Åmmebergs gruvor.
In the early twentieth century the workforce and infrastructure grew. A community building, Folkets Hus, was completed in 1910 to serve the growing mining settlement. In 1940 the first underground loading machine was introduced, allowing more efficient mechanised ore handling in the deeper levels. The centennial of production was marked in 1957 amid sustained output of zinc, lead and silver concentrates.
A major reorganisation took place during the mid-1970s. The decision was made to expand production capacity significantly to 600,000 tonnes per year. A new shaft, P2, was sunk to access the deeper ore reserves, and a new concentrator and tailings impoundment were established immediately adjacent to the mine site, replacing the remote Åmmeberg facility. The Åmmeberg processing plant closed between 1975 and 1977, and the concentrator at the mine came into operation; sources indicate it was built in 1977. This consolidation marked a decisive transformation in the mine's physical layout, with the processing plant now located next to the P2 hoisting shaft.
In the early 1990s, new technology and careful operational management reduced mining and milling costs by approximately 50 per cent, converting what had been a high-cost operation into one ranked sixth-lowest-cost zinc producer in the Western world by 1993.
Vieille Montagne merged with Union Minière in 1990. North Limited of Australia acquired Union Minière in January 1996, subsequently renaming the Swedish operating entity Zinkgruvan Mining AB in 1997. North made substantial investments in the operation before itself being acquired by Rio Tinto in August 2000.
In June 2004 Lundin Mining, operating at that time as South Atlantic Ventures, acquired the mine from Rio Tinto for USD 101 million. The company subsequently reviewed operations using updated planning tools, and production averaged 739,000 tonnes per annum over the period 1998 to 2003. In late 2004 Lundin sold the future silver production stream from Zinkgruvan to Silver Wheaton Corp. for an upfront consideration of USD 50 million in cash plus shares and options.
Under Lundin, the concentrator capacity was increased progressively. An ABB process control system was installed in 1999. The existing flotation cells were replaced with 22 larger Svedala RCS cells to increase retention time and expand capacity from 600,000 to 750,000 tonnes per year. A further expansion launched in 2007 increased mill capacity from 900,000 to 1.2 million tonnes per annum, incorporating a 5.5-kilometre surface access ramp decline to 350 metres depth, an underground ore bin, and a dedicated copper processing circuit. First production of copper concentrate was achieved in 2010. The copper treatment line, rated at 0.3 million tonnes per annum, was further modified in 2011 to allow processing of zinc-lead ore as well as copper ore. Mine access by that point comprised principally three shafts, supplemented by the new ramp.
In 2009, zinc output reached 51,370 tonnes and lead output 25,894 tonnes, with silver production of 1,356,003 ounces from treatment of 720,679 tonnes of ore. By 2022 annual ore throughput reached 1.46 million tonnes with turnover of approximately SEK 3 billion. In 2024, under Lundin's final year of ownership, the operation achieved record output of 82,133 tonnes of zinc and 30,888 tonnes of lead.
Boliden AB agreed to acquire Zinkgruvan Mining AB from Lundin Mining in December 2024, alongside the Neves-Corvo mine in Portugal. The transaction completed on 16 April 2025 for a cash consideration of USD 1.40 billion, with contingent payments of up to USD 150 million tied to commodity prices. Boliden had no previous ownership interest in the mine. At the time of transfer, Zinkgruvan employed approximately 480 people and was the largest private employer in Askersund Municipality. The operation continues as Sweden's southernmost active underground mine, processing approximately 1.43 million tonnes of ore annually to produce zinc, lead, copper and silver concentrates for European smelter customers.